Of late, there have been produced tape recorders with many different selectable conditions, so that the operation of the tape recorders has become more complicated. For example, a recording or reproducting condition may be selected according to the magnetic characteristics of a magnetic tape used so as to improve a playing characteristic, and a main sound signal is processed so as to be compressed at its recording and be expanded at its reproduction to get a good signal to noise ratio. In this case, an operator has the choice of selecting the time constant of recording and reproducing circuits depending on the magnetic characteristics of the magnetic tape used and the choice of selecting use or non-use of a noise reduction circuits. Therefore, the operator is required to select the reproducing condition or characteristic of the reproducing circuit at reproduction in accordance with the recording operating condition or characteristic selected. Thus, the recording operating condition or characteristic has been usually indicated on a carton in which the magnetic tape is contained. However, it has been frequently experienced that the indications on the carton tend to disappear during use. Otherwise, it has been frequently experienced that the operator has not indicated these conditions on the carton. Thus, the operator hesitates in the selection of the reproducing or playback operating condition.